Before the invention is described in detail, it should be mentioned that the technique for chip removing machining of above all workpieces of metal is quickly developing. When blanks or workpieces previously were machined to finished products having some complexity, such as engine components, vehicular and craft components, machine parts, etc., the manufacture was carried out in a plurality of steps or stations, which individually required separate set-ups of one and the same blank. For instance, a first machining could be one or more turning operations. If the detail also required different forms of recesses, such as keygrooves or bar grooves, the same was moved to a new set-up of another station, where milling followed. Should the same in addition be provided with different forms of holes or ducts, transfer was carried out to an additional set-up of a drilling machine or drilling station. More recent, machines were developed in which a magazine is included having a large number of tools, each one of which can be picked out of the magazine and brought to an active state for machining, and which after accomplishing the machining is brought back to the magazine to be replaced by another tool.
In order to make the manufacture more effective and reduce the times for, as well as the costs of, the machining, universal machines have recently been developed in the form of so-called MultiTask machines, in which a large number of program-controlled tools are included, which are flexibly movable in space and capable of executing multiple machining operations, such as turning, milling, drilling, grinding, etc., without the workpiece having to be removed from the machine or the set-up thereof in the same, and in which the need of time-consuming tool exchanges is reduced to a minimum. In such universal machines, partly new requirements are made on the tools in question, not only in respect of their capacity to execute conventional as well as new machining operations, but also in respect of the accessibility of the tools so far that the individual tools should be able to move in complicated paths of motion within a limited space and in spite of this be able to come into contact with those parts of the blank being machined which are difficult to access. This applies not at least to milling cutter tools, e.g., of the type that is used for the milling of notches of different types.
A previously known milling cutter tool is described in SE 0400385-1 (publication number 526.645). This known tool includes a plurality of peripherally spaced-apart cutting bodies having teeth, which are orientated perpendicularly to the underside of the individual cutting body, two or a plurality of teeth being situated in a common plane, which extends perpendicularly to the center axis of the basic body. This means that axially co-situated teeth will operate in one and the same notch in the form of a straight notch, the teeth alternately engaging the workpiece after a certain rotation of the tool. This tool is useful for a plurality of different milling operations, but not for gear hobbing.
The present invention aims at obviating the above-mentioned shortcoming of the previously known milling cutter tool and at providing a milling cutter tool, which is suitable for gear hobbing, in particular in MultiTask machines.
An object of the invention is to provide a milling cutter tool, which is designed in such a way that the same can, by simple feeding motions, be utilized for gear hobbing, in particular for the creation of bars or teeth in details having a rotationally symmetrical, usually cylindrical shape.